Study of coupled pyrite leached pyrolusite by functional microflora

Abstract:

[Objective] Three different environmental samples were mixed and inoculated into 100 mL fresh medium containing 1% pyrolusite and 1% pyrite. After enrichment we got bioleaching microflora. [Methods] Obtained microorganism consortia were used to leach pyrite and low-grade pyrolusite. Non-inoculation system was conducted as control group. [Results] Series of parameter were monitored during the process, including dynamic of consortia construction, pH value, leaching ratio of manganese, and XRD analyze of leaching residual. Leaching ratio of manganese was 92.48% after 15 days cultivation. And it was much higher than control group (40.34%). Within microbial consortia, Thiomonas sp. was the dominant species and its proportion increased from 2% to 93% of the consortia. Value of pH was declined from 4.0 to 2.5 in experimental group. Jarosite was observed in bioleaching residual. [Conclusion] Decrease of pH value and formation of jarosite indicated abundant sulfuric acid produced by bacterial metabolism. Result suggested that increasing bioleaching ratio of pyrite and pyrolusite due to dissociation of pyrite and decline of pH value by bacterial activity. This study could provide the basis for the further research of bioleaching mechanism and improvement of industrial art of low-manganese ore mineral resource.